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Radial gradients of ion densities and temperatures derived from SWICS/Ulysses observations
Author(s) -
Liu S.,
Marsch E.,
Livi S.,
Woch J.,
Wilken B.,
von Steiger R.,
Gloeckler G.
Publication year - 1995
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/95gl02595
Subject(s) - ecliptic , solar wind , physics , ion , proton , interplanetary medium , solar energetic particles , heliosphere , interplanetary spaceflight , astrophysics , particle (ecology) , plasma , computational physics , atomic physics , atmospheric sciences , coronal mass ejection , geology , nuclear physics , quantum mechanics , oceanography
Mean density and temperature gradients of solar wind protons and α particles are derived from SWICS/Ulysses observations between 1.2 and 5.4 AU in the ecliptic plane during declining solar activity. All parameters are sorted in solar wind speed classes. The radial gradients show a similar behavior for both ion species. In the slow solar wind protons as well as α particles are found to expand adiabatically all the way out to many AUs, while in the fast wind ions evolve non‐adiabatically and are heated by interplanetary sources. The α particle to proton temperature and density ratios are also determined. They do not show any clear radial dependence.